How to size an engagement ring
Measure the body part, then add ease
Ring size is finger circumference at the base of the finger, where the ring sits. Measure at the end of the day when fingers are at their largest, and never on a cold morning. The same finger can vary by half a size between seasons.
Standard length names
US sizes use whole and half steps (4 to 13). UK uses letters (G, H, I…). EU uses circumference in mm (e.g., 52 mm = US 6). The finger sized for a wedding band is typically the same as for the engagement ring; if they'll be worn together, account for the band's thickness.
Sister sizing for in-between measurements
If your measurement falls between two sizes, the safer pick is usually the longer one — an extra link or 1/2″ of slack can be hidden by the clasp position, but a too-tight piece either won't close or wears the chain at the same friction points and breaks earlier. Look for adjustable extender chains (typically 1–2″) when the measurement is borderline.
Common mistakes
- Measuring the wrong reference point (necklace lengths are measured from clasp to clasp; bracelet lengths include the clasp).
- Confusing US and EU sizing — cm and inches are not interchangeable on the same chart.
- Forgetting that pendants and charms add visible length to a chain.
- Buying for the "perfect" fit on day one. Slight ease is what keeps the piece comfortable as the body shifts during the day.